Coumarone-indene resin stabilized with an alkyl polyhydroxy spiro indane



Patented Feb. 22, 1949 -OUMARONE-IND'EN ALKYL P E RESIN STABILIZED OLYHYDROXY SPIRO "Samuel G. Burroughs, Pittsburgh, :Pa., ,assignor to Pennsylvania industrial Chemical Corporation, clairton, Pa., .a corporation of Pennsyl- 'yania .NoiDrawing. Application January 18, 1945, 'SerialNo. Bil-3,469

This invention relates to improvement in coumarone-indene'resin polymers; and bears therelation of a continuation-impart to my applicationlSerial No. 197;039, filed August 2, 1943, which has become, abandoned.

A property of coumarone indene resin which detracts from the utility of the resin asan ingrient of coating compositions is its tendency-to discolor, or yell'owi This discoloration takes place very rapidly'when'th'e resin forms orisineluded in-:a film-suchas a paint or varnish 151m .02 a protective filmfor concrete. It is induced by oxidation, and the progress "of the oxidation and discoloration is greatly accelerated by sub- 'jection't'o light containingultra-violet* rays. This tendency to :discolor, or 'yellow, takes place-in spite of the care 'exercised'in making the resin, andtthe phenomenonoccurs in'coumarone-indene resins of evenxthe-greatestpurity andlightest-initial color. Thus if a. coumarone-indene resin of maximum purity and initially a very light yellow color "be spread *in an apparently colorless fllm'; ,such film 'will show 'a marked yellowish cast after subjection to bright sunlight 'for only a few (days, and "the 'color development will progress *to a stage in Whichthe color of the film is "a brownish yellow -or "yellowish brown.

Resort to various expedients -hasbeen taken,

to inhibit color development in coumarone-indeneresin'by saturation or partial saturation of the polymeric "-molecules'of the resin. 'The best known andprobablythe most effective method of so doing is "by hydrogenation. "Hydrogenation is .an expensive procedure, and 'because it greatly increases the solubility of the resin is practiced chiefly for uses of *theresinin which solubility of the resin-inaliphthatic hydrocarbons is -a prime requisite.

VIt i 'the object of my invention 1 to provide in a manner to-render large scaleproduction of the resin commercially praetical;a coumarone-iridene resin in which color developmentis prevented, or is *reduced'to an'order inwhichit does nct substantially detract "from the value 6f the resin in no ating compositions.

-I have discovered that discoloration of coumarone-indene polymers When'use'd-alone, orwith other ingredients of film-forming compositions, adhesives elastic or plastic bodies, *and the like, "maybe renderedneg'lig'ible'by including with the coumarone-indene polymers an anti-oxidant of special kind. There 'a substantial :number of anti-oxidants currently used to prevent, -(i. e. to render negligible) oxidation in gasoline and 5m rubber. Most :of such anti-oxidants, such as paraamino phenol, alpha 'naphthalamine, ,phenyl beta naphthalamine, benzoylamino phenol, diphenylamino ethane @and the aldehyde aminereaction productstare relatively ineffective ,in preventing discoloration of coumarone indene polymers. Whereas they serve to retard color-development, they do not prevent the resin from obtaining ultimately .a color depth ,almost equal to that reached when anti-oxidants are absent.

I have discoveredhowever, that the inclusion \vithrcoumaronesindene polymers ,ofa small quantity of .aparticularclass of anti-oxidants is effective .to prevent color development in the coumarone-indene ,lpolymers. This class of anti-oxidants consistslof the alkyl polyhydroxy spire hydroindenes, nor in the preferred nomenclature of Chemical Abstracts-of the-American Chemical Society, the alkyl polyhydroxy gspiro indanes. Such compounds ,are characterized ,by morepo r less rcomplex structure presenting unsaturated ring :nuclei with hydroxyls, and saturated ring structure joining the unsaturated nuclei. ,These compounds and the \methods involved in their preparation are described. ,in-various publications,

among which are apaper by Fabrinyl and ,Szeky,

Berichte der Deutchen-Chemischem ,Gesellschaft, vol. 38, ,page 2,307 (1905), and in an article :by Baker, Journal of Chemical .Society (London) .1934, page16'l8. ;Me tho.ds involving the use of such compounds to prevent oxidation in rubber, by, including with the: rubber such anti-oxidants, aredisclosed-inmy .-P atent No. ll-76,881, issued ,Octoberflti, 1939.

,As exemplary 10f the allgyl; poly-hydroxyindanes, I may give 3,3,3,3 :tetrame hyl 6,637,7 tetrahydroxy 1,1 spiro bis;indane;i 3,3,3',3' tetramethyl 4,4,5,5', tetrahydroxy 1,1, spiro bis-indane; 3,3,3',3' tetramethyl 5,6,5,6 tetrahydroxy 1,1, spiro bis-indane; 3,3,3',3' tetramethyl 4,5,6,4,- 5,6 hexahydroxy "1,1 spiro bis-indane; 3,3,3,- 3',5,6,'7,5",6',-7' hexahydroxy 1,1" spiro bis-indane; 3,3,3',3' tetramethyl 5',5' -;'dihydr ogy 6,6 dimethoxy 1,1 spiro bis-indane; 3,3,3',3' tetramethyl 5,5 dimethoxy 6,6 dihydroxy 1,1 spiro 'bis-indane; 3,3 'dimethyl 3,3 diethyl 5,6 diethoxy 5'36 dihydroxyhl spiro bis-indane.

The formula for *3,*3,3',3"tetramethyl 5,6,5,6' tetrahydroxy 1,1 ,spiro bis-ind-ane ;may be taken; aszrepresentative. .Ilhecurrentlyaccepted and apparently sound formula for that substance may be given as follows:

HaC

/ CHz The melting point of the above compound is from 280 C, to 285 C., with some attendant decomposition. Like all the alkyl polyhydroxy indanes, it is soluble in acetone and other ketones, sparingly soluble in low boiling aliphatic solvents, and insoluble in water. 7

As described in the articles to which reference has been made above, the alkyl polyhydroxy spiro indanes are best prepared by condensing polyhydroxy phenols with ketones in an acid medium, such as an acetic acid-hydrochloric acid mixture. The desired compounds are insoluble in such ameclium, and are precipitated as condensation proceeds. The alkyl polyhydroxy indanes for preventing color development in coumarone-indene resin may be prepared by condensing such phenols as catechol, pyro-gallol, phloroglucinol, quinol, and 1,2,4 trihydroxy benzene with such ketones as acetone, methylethyl ketone, methyl-propyl ketone, and ethylpropyl ketone. If the ketones of higher molecular weight be used, a lesser yield of condensate is had, but such ketones are usable.

I have discovered further that sulphonation products of the alkyl polyhydroxy indanes, and boric acid salts of the alkyl polyhydroxy spiro 'indanes are similarly efiective to prevent color development in coumarone-indene resin.

As exemplary of sulphonation of the alkyl polyhydroxy spiro indanes, I shalltake a tetramethyl 5,5',6,6 indane. One part tetrahydroxy 1,1 spiro bisby weight of that material was added to 3 parts by weight of 65% oleum (65% S03 and 35% H2804) at 0 0., and was agitated for complete solution therein. Agitation was continued until a small sample, taken out, was soluble in a large amount of water. The reaction product was poured into water and was neutralized with calcium hydroxide.

The mixture was filtered and the filtrate was precipitated by treatment with sodium carbonate until no further precipitation took place. The precipitate was filtered out, and was evaporated under vacuum to obtain the sodium sulphonate of the spiro indane. phonation takes place at all four positions 4,7,- 4 ,7, but the following formula for the sulphonated indane is theoretically possible:

OHQ HO 4' some NaSO: 7 O

mo H

resin, the metallic or organic base salts of an acid-reacting complex formed by reacting an alkyl polyhydroxy spiro indane with boric acid. The preparation of such alkyl polyhydroxy spiro indane-boric acid salts is exemplified by the following:

An alkyl polyhydroxy spiro indane and an organic base, such as diphenylguanidine are dissolved in equal molecular proportions in acetone with warming. Boric acid is added to the solution in molecular equivalency with the spiro indane, and the mass is warmed. The solid material which isformed is digested with warm water and is filtered. The material thus formed is a fairly stable spiro indane-boric acid salt. This salt is particularly desirable for use in compositions which contain an acid substance with the coumarone-indene resin. This is because the presence of an acid tends to lessen the efiectiveness of the alkyl polyhydroxy spiro indanes in preventing discoloration of the coumaroneindene resin, and the boric acid salt of the spiro indane is more capable'of resisting the efiect of the acid.

To prevent yellowing of the coumarone-indene resin, I include with the coumarone-indene polymers of the resin from about 0.05% by weight of an alkyl polyhydroxy spiro indane material selected from the alkyl polyhydroxy spiro indanes,

.' the sulphonated alkyl polyhydroxy spiro indanes,

and the alkyl polyhydroxy indane-boric acid salts. Quantities up toand even in excess of 5% of these substances do not tend to detract from the coherence .and other film-forming properties of the resin. It is a fact that the alkyl polyhydroxy spiro indanes are not highly soluble; and that from 3% to 5% is the greatest proportion of them that will remain associated with the polymers of the resin without precipitation from evaporative solvents or incompatibility with nonvolatile plasticizers, for the coumarone-indene resin. In most instances, as has been noted, a small quantitiy of the alkyl polyhydroxy spiro indane materials is adequate to prevent yellowing of a coumarone-indene resin with the polymers of which it is associated. For some purposes, however, alkyl polyhydroxy spiro indanes in excess of 5% the weight of the coumarone-indene polymers usefully may be associated with them as a minor content of the non-yellowing coumarone-indene resin.

With a very pure low'molecular weight coumarone-indene resin in solution in a solvent such It is not certain that sulas mineral spirits, from 0.1% to 0.3% of the spiro indane itself usually is adequate. If, however, the resin should have a perceptible content of phenols, or other acidic content, from 0.1% to 0.3% of the boric acid salt of a spiro indane or at least 0.4% or 0.5% of' the spiro-indane itself should be included in the solution. If a solution is to be made of a high molecular weight coumarone-indene resin insoluble in mineral spirits, (which resin is of high purity), and dissolved in a suitable solvent such as high flash solvent naphtha, from 0.05% to 0.2% ofthe spiro indane itself usually is adequate. In the case of a plastic composition composed of coumarone indene resin, plasticizing materials and fillers in which one or more of the components additional to the coumarone-indene resin is acidic, from dane is used, the proportions of that material desirably included follow very closely the proportions given for the spiro indane itself.

In all the foregoing the proportions of the spiro indane materials are based upon parts by weight of the coumarone-indene polymers in the solution or composition. Customarily the coumarone-indene resin' is made up for sale and use as a solution or composition, and in the case of a solution, the spiro indane material is associated with the coumarone-indene resin in the solution. If it is desired, after including the spiro indane material, to distill off the solvent and thus to obtain a solid coumarone-indene resin including the spiro indane, it is necessary to include a substantially greater quantity of the spiro indane material, such as from 2 to 4 times the proportional quantities given above, in order that the prescribed proportion of the spiro indane material will be included in the solid coumarone-indene resin. This is because there is some loss of the spiro indane material during distillation. It appears, however, that the spiro indane material is effective to prevent discoloration of the coumarone-indene resin when used either by associating it with the coumaroneindene polymers in solution, by associating it with the coumarone-indene polymers in a solid or semi-solid composition, or by associating it with the polymers of a resin.

The following examples illustrate ples of my invention:

Example N o. 1

A light-colored coumarone-indene resin of low molecular weight melting about 70 0. (ball and ring) was dissolved in an equal weight of mineral spirits. A tetramethyl tetrahydroxy spiro indane in' a quantity equal to 0.3% the weight of the coumarone-indene resin was dissolved in acetone and was added to the resin solution. The acetone solution of the spiro indane included a small quantity of the mono-ethyl ether of ethylene glycol, in order to prevent precipitation of the spiro indane. The spiro indane was mixed thoroughly with the coumarone-indene resin solution.

The solution so formed was adapted to filmthe princiformation by evaporation of the solvent to leave a film of coumarone-indene resin. Upon formation of such film by evaporation in air, and upon re-dissolution and analysis of the resin forming the film, it was found that most of the spiro indane remained with the resin in the film, there being but slight loss of that material during the course of normal evaporation.

A film of the deposited resin when exposed to ultra-violet light in a Weathermeter for 24 hours showed no definitely ascertainable discoloration. Exposure to sunlight for three weeks caused no greater color development in the film. A film of an identical resin solution, but containing none of the spiro indane became very yellow when exposed to bright sunlight for 12 hours.

Example No. 2

A light-colored high molecular weight coumarone-indene resin, melting about 130 C. (ball and ring), was dissolved in an equal weight of high flash (coal tar) solvent naphtha. A diethoxy-dihydroxy-dimethyl-diethyl spiro indane was added in acetone solution in a quantity equal to 0.15% the weight of the coumarone-indene polymers in solutions. The spiro-indane was solid coumarone-indene 6 mixed thoroughly with the coumarone indene resin solution.

A film of resin deposited from the solution by evaporation of the solvent was exposed to ultraviolet light in a Weathermeter for 24 hours. Exposure to sunlight for three weeks caused no greater color development in the film. After such exposure, the film was but very slightly colored.

Example N0. 3

A light-colored coumarone-indene resin of low molecular weight, melting about 60 C. (ball and ring), was dissolved in its weight of mineral spirits and an emulsion was formed by agitation with a small amount of triethanolamine-oleic acid soap. There was agitated with this emulsion tetrahydroxy tetramethyl spiro indane sodium sulphonate in a quantity equal to 0.2% the weight of the coumarone-indene polymers in the solution. The emulsion was diluted with an equal volume of water and was allowed to stand in a bottle exposed to sunlight. After a period of 3 weeks, nodiscoloration was detectable.

Erample No. 4

Example N0. 5 With the same plastic composition as in Example No. 4, there was added 1.0% of tetramethyl tetrahydroxy spiro indane. As in Example No. 4,

r the mass was mixed well, was plastered on a slide,

and was exposed to sunlight. After exposure for 30 days, there was a relatively slight discoloration, which discoloration was more marked than in the material of Example No. 4, but was strikingly less than that which took place in a composition containing the same ingredients, save that no spiro indane material was included in association with the polymers of the coumarone-indene resin.

Example No. 6

A light-colored coumarone-indene resin of low molecular weight, melting about 70 0. (ball and ring) was dissolved in an equal weight of mineral spirits. A tetramethyl tetrahydroxy spiro indane in a quantity equal to 0.6% the weight of the coumarone-indene resin was dissolved in acetone and was added to the resin solution. The acetone solution of the spiro indane included a small quantity of the mono-ethyl ether of ethylene glycol in order to prevent precipitation of the spiro indane. The spiro indane was mixed thoroughly with the coumarone-indene resin solution.

The solution so formed was subjected to distillation with steam, care being taken to utilize a temperature no greater than required to distill off the solvent. The solid coumarone-indene resin was recovered.

Upon analysis the solid coumarone-indene resin was found to contain about 0.3% of the spiro indane. Upon re-dissolution in mineral spirits and uponrzdepositionwof the resin inrarfilm,iitheefilm was found to possess the same resistance. :to yeL lowing that was possessediby the film -deposited fromrthe solution of 1coumarone=indene polymers innssociation with thespiro'indane'made in accordance with'the proced-urexof ExampleNo. 1.

Example No; 7 A light-colored coumarone-indene resin of high molecular weight, melting about 130 C. (ball and ring) was fused. With this fused resin there was mixed tetramet-hyl tetrahydroxy spiro. indane in ajquantity equal to.0. 6% theweightof thetre'sin. 50.:parts by'weight of the-resin-were Workedup with. 20 parts by weight of ;dibutyl phthalate and 30 parts by weightof white (titanium oxide) pigment. The mass thus formed when exposedto ultra-violet light in a Weathermeter for 48 hours developed only slight discoloration.

Example No. 8

;A low .molecular weight coumaroneeindene resin:meltingzabOut-fiO 0. (ball and ring), was fused,:and tetramethyl tetrahyd-roxy spiro indane borate in a quantity equal to 0.4% the weight of the coumarone-indene resin was worked thoroughly into the body ofzthe resin. 25 parts by weight .of this treated coumarone-indene .resin wasmixedwithj25parts by weight of .blown soya bean oil, a'nd;50..pants byweight of precipitated calcinmicarbonate.

g.YIlhis.composition-appearedin its resistance to discoloration and. in all other properties closely similar to. the composition made. by'bringing. the spiroindane intoassociation with the coumaroneindene, .p lymers;.in accordance with the .procedureofExampleNoA.

I It 'is...corr ect to sayanyv member of. the group consisting of the. alkyl. polyhydroxy sDiroindane materials above disclosed, namely the alkyl polyhydroxy spiro indanes;-'themselves, the sulphonated .allgyl polyhydroxy. spiro indanes,. and...the boric acid saltsof. thealkykpolyhydroxy spiro indanes, when associated with 'the polymers .of coumarone indene resin prevent yellowing of the resin. Tha;t"is,..they'not only greatly retard yellowing'but prevent permanently what may be considered. the normal color development of each individual coumarone-indene resin. It .is'to 'be understood that the :foregoing examples are'eX- emplary only of' the :ways in which the specified s iro indanes can be. associated .efiectivelywith the polymers .of.coumarone-indene resin.

' Where proportionsgmay-haverbeerr stated without qualification throughout'the. foregoing-specification, such proportions are to betakenwas in parts by weight,-and wherethroughout the specification melting.;point of resinshasbeengiven without qualification, that melting, point. is to:..be taken as by the ballzand ring method of melting point determination for resins.

: I'claim as my invention :.1. :A non-yellowing coumarone-indene resin compositiomconsisting of coumarone and indene polymers and an alkyl polyhydroxy spiro. indane material selected from the group consisting-ofthe alkyl polyhydroxy; spiro indanes, the. sulphonated alkyl .polyhydroxy spiro indanes and the borlc acid salts .of the .alkyl: polyhydroxy. spiro indanes, the .said alkyl polyhydroxy .spiro, indane material being present in a quantity approximately equal to from 0.05% to 5.00% the combined-weight of t-hecoumarone and indene polymers.

:2. A non-yellowing coumarone-indene "resin composition consisting of coumaronezand indene polymers and an al'kyl'polyhydroxy spiro'indane in a quantity-approximately equal to-fr0mf0:05;% to 5.00% the combined weight of the coumarone and indene polymers.

3. A non-yellowing coumarone-indene resin composition consisting. of coumarone :and indene polymers and a .sulphonated'alkyl polyhydroxy spiro indane in a quantity approximately-equal to from 0.05% to 5.00% the weight of the coumarone-indene polymers.

4. A non-yellowing couma-roneeindene .resin composition consisting of coumarone and indene polymers and an alkyl polyhydroxy spiro indaneboric acid salt in a quantityequal to =from0l05% to 5.00% the weight'of the coumarone-indene polymers.

SAMUEL G. .BURR'OUGHS.

REFERENCES CITED The following references are of record in'the fileof this patent:

UNITED :STATES PATENTS Number Name Date 2,139,722 Carmody Dec. 13,1938 2,176,881 Burroughs Oct. 24, 1939 2,176,882 Fisher Oct. 24,1939 2,176,883 Fisher Oct. 24,1939 

